Book cover



Feb. 25, 1.930. A, M- MARTlN 1,748,236

BOOK COVER Filed 00T.. '1, 1927 Patented Feb. 25, 1930 PATENT OFFICE ALFRED M. MARTIN, OF CHICAGO, ILLINOIS BOOK COVER Application filed October 1, 1927. Serial No. 223,276.

These improvements relate to lids or covers for books. An important application of the 'inventionis to large-size loose-leafy binders having prongs or other means for holding the sheets. My Patent No. 1,269,479 of June 11, 1918 shows a binder adapted to accommodatemany series of sheets with the sheets of each series inv overlapped relation. In such binders the accumulated thickness y and corresponding weight of the middle portion of the mass of sheet material impose unusual strains upon the middle. portions of the lids or covers in handling and especially upon the marginal portions of the covers not supported by the sheet ymaterial within. To provide covers for the large-size and heavy books orfbinders which will withstand the hard usage imposed on them and retain their Y normally flat shape against warping and such .unusual strains has yproved a diflicult problem and one which many persons have sought to answer and in various ways. In my copending' application filed January 31, 1927 as Serial No;"164,692 l'on ibook covers I have shown how the desired results may be attained to a notable extent. The present improvements providevan unusually strong and durable cover and one which though forced awry or out of its normal plane from time to time during long-continued handling with spring back and maintain its normally plane f character or shape. One feature of improvenient is in a construction involving a metal binding which will notmar furniture, such as the table top on which the book or binder is placed during normal usage. @ther objects and advantages will appear hereinafter.

yIn the drawings Fig. 1 shows in end view and in open position a book-type binder having lids or covers ofthe present invention applied thereto; Fig. 2 is a side view of such a bindery closed; Fig. 3 is an enlarged fragmentary and partially broken-away side View of the'binder of Fig. 2 in corresponding posi- 15 tion; Fig.v4 is a further enlarged sectionalk ,tion 14 according to common practice and view of the cover as on the line 4 4 of Fig. 3 and Fig. 5 is a perspective of one of the reinforcing members shown sectionally in Fig. 4.

The lid or cover 10 comprises first a rectangular body of fiat sheet material denominated 11 as a Whole in Figs. 2 and 3. This body maybe variously constructed. It is common to make such a body of laminations of cardboard, fibre, etc. or of single sheets of material. An advantageous construction of the plate-like body 11 when employed with other features shown herein is illustrated in Figs. 8 and 4. There is first a strong sheet of cardboard material 12 which may be say thiee-siXteenths of an inch thick for the larger 6 books. This sheet 12 is covered by an outer finishing sheet 13, which may be of cloth or of any other suitable surfacing material. The main sheet 12 is beveled at its inner edge porthe. surfacing sheet 13 is shown as passing around the beveled inner edge of the sheet 12. Next in order is the hinge leaf 15 extending along the inner edge portion of the cover adjacent to the associated back member 9. A770 kcardboard sheet -16 of the thickness of the hinge leaf abuts yand terminates at the hinge leaf and covers the rest of the normally inner surface. of the main sheet 12. Another lainination 17 of thin cardboard covers the hinge y 75 leaf and the sheet 16 and incidentally covers the inner heads of the rivets as 18 holding the hinge leaf upon the main sheet 12.- Then follows the inner surfacing sheet 19, usually of paper. Thesek laminationsare glued one upon another and tightly compressed in the usual way. f

Tightly crimped upon the three outer marginal edge portions of the body 11 is a continuous metal binding rim R, preferably circular in cross view, having rounded corners at 22 and 23 and having its inner ends, normally adjacent to the back members 9. turned inward at 24 and 25. This out-er binding frame, merely as a tubular frame, and without the inturned ends at 24 and 25, is shown in myV said copending application, of which this application is a division with respect to the rim. n

Fig. 4 shows the cross-view shape of this rim member R. It maybe formed by preliminarily rolling flat stock such as cold rolled steel of about 20 gauge into a somewhat tubular form but with the edges spaced apart sufficiently to admit edge portions of the body ll thereinto. The dotted lines of Fig. 4 show this preliminary stage. The next operation is to bend the formed strip into a substantially iJ-shaped member having corners at 22 and 23 rounded in they planel .of the cover and also inwardly-directed rounded ends at 24 and 25. The rim thus formed comprisesan upper member 26, a lower member 27, and a side member 28. The body as ll is then inserted between the upper and lower rim members" 26 and 27 and then the rim may be crimped tightly upon the sheet material as 'shown by Fig. 4.

The present improvements contemplate that for large-size' books reinforcing, as the strips 30, 30a and 30b will be employed, but the rim formed from a single piece of any appropriate metal, with rounded corners at y22 and 23 is a notable improvement over binding rims heretofore suggested, and the inturning of the ends at 24 and 25 in the plane of the cover makes for a still further improvement. Y

For the large-size covers I have found that even the continuous frame Of'VQO-gauge coldrolled steel has not the required characteristics forv the heavy and repeated strains imposed. For such covers I add strong and springy reinforcing material, preferably "in the half round strip Aform of Fig. 5. In assemblingV the parts including' the reinforcing as 30 the body as 11 is inserted between the upper' and lower rim members 26 and 27 until the side edge of the body is a short distance 'from the entrance tothe side rim member 28,

, and at this stage the reinforcing element 30 is inserted in the frame member 28 to occupy its relative position shown by Fig. 4, and then the rim and. body are further telescoped together until thebody abuts the reinforcing element 30 as shown in Fig. 4.

The next operation is to insert similar reinforcing strips marked 30a` and 30b in the rim members 26 'and 27 respectively. These may simply be forced in from the free ends of the Y rim, the upper and lower rim members being sprung apart slightly to facilitate the operation. In all instances the reinforcing niembers 30,V 3'()a and 30 are continuous strips reaching from one rounded part of the rim member to the other, as well illustrated in Fig. 3.

. The next operation is to crimp the rim upon the plate-like body. This is most conveniently done in a press having suitable dies,

yand Vall as a single operation. When so crimped the material of the body is indented,

as shown in Fig. 4, and the rim is thus Very tightly and securely held upon the body. At the same time the reinforcing as 30, Fig.k 4, preferably having the half-round shape of the hollow interior' in cross view, is veryl tightly bound within the rim.

The reinforcing materialras 30 is in strip form having substantial width in directions at right angles to the plane of the cover` as a whole. For the best results it should be of highly springy material, for example, steel of the kind used for making slender fishing Y' rods.k Y y There are particular reasons forthe rim construction thus described. It might be suggested vthat the hollow rim be made of.

rolled steel Vthere would be difficultyy in obtaining the proper crimping effect, due to the springiness of the metal, and' there would be a further objection due to the want of sufficient metal inthe rim to withstand the knocks and bumps received in use." After many experiments with many different kinds of metal suitable for the purpose I haverascertained that the cold-rolled half-hard steel of about 20-gauge is most suitable for the rim in view of the manufacturing'requirements as well as those ofwear. Such a mere'ri'm,

however, is likely to develop avpermanentdisv tortion out of the normally flat planel of the cover in the larger-sized books or binders,

i particularly when of the kind havinga heavyi mass of sheet mat'erialin the middle of the book.

The book is almost'necessarily han-l dled by grasping it around marginal portions v of the opposed covers, bending them toward yeach other, particularly at the top and bot-vv tom portions where the Vsheet material between tlie covers is not Vas, thick as itis inthe f middle. By insertin@ the strong and resilient reinforcing members 80, 30d and 301 means `are provided for maintaining the covers in their normally flat shape, for although the covers will be sprung out of thel plane, even with the reinforcing stripsV therein, yet the nature of the'y construction is new rsuch asto restore the cover to its flat shape.

cover of this disclosure a permanent set, Vbut the ordinary strains upon them in practice are not lenough to do so. f Without the reinforcing the objectionable permanent set awry does not occur at any one time but as a resultV of many repeated strains, each one leaving a course it would be possible to ygive eventheV furthermore, the elastic limit of the parts is increased owing to the resiliency of the reinforcing strips.

It would be armarked improvement if a reinforcing strip were applied to any one of the three rim members, especially to the side rim member 28, but the best results are had when it is applied to all three as shown. The present construction may be employed without sacrificing the advantages of lightness of the vcover as a whole. Indeed I am thus' able to produce a cover having the advantages herein pointed out which is even lighter than covers heretofore found necessary to withstand ordinary usage and which, notwithstanding, suffer greatly from the deforming strains.

An important feature of improvement is in the inward rounding of the ends of the rim at 24 and 25v in the plans of the cover, whether the reinforcing is used ornot. This inward rounding has several important functions. In the first place it strengthens the rim where the rim is crimped tightly upon parts including the hinge leaf 15, and since the weight v and strains of the mass of sheet material and the bookA as a whole is communicated to the covers through the hinge lugs this feature of diverting these strains to a large extent to the rim isa valuable and important one. An-

other advantage of this construction is that there is thus produced rounded surfaces where the rim comes upon the table top as illustrated in Fig. y3, and the table top is saved vfrom being marred by the contact. The

rounded construction at these places also feels better in the hands of the user,.and it also gives the cover a better appearance.

The cover 'as a whole is peculiarly pleasing in appearance and in handling. The circular shape of the rim in cross view provides smooth surfaces which do not mar furniture,

which is true also of the rounded corners at 22 and 23. The rounding of the corners at 22 yand 23 taken with the continuous formationv .of the rim provides a peculiarly strong corner where the shocks are often very severe, and the cover is thus saved from the breakage and mushy character of the corner portions so common in ordinary practice. `Heretofore it .has been'common practice to apply to the lids .i separate metal corner pieces in order to overcome the serious objections referred to; but

such corner pieces have not met the require# ments since the corners would break olf or bend bodily and in practice sharp edges and projections were presented at the joints,

especially after some bending or breaking effects.

In binders of the kind herein referred to it is customary to have the lids extend slightly beyond the back members as 9 to protect these back members. This construction is in` dicated by the space at 33 between the back member as 9 and the horizontal support. In

such a binder the rim R is peculiarly important in the safety it provides against the mushy condition so commonly found in the lower edge portions lof the lids due to the impacts of handling. The rounding of the inner ends of the rim at 24 and 25 is therefore at somewhat exposed portions of the lid and avoids the occurrence of sharp elements at these places likely to cause damage.

I contemplate as being included in the present improvements all such changes, variations and departures from what is thus specilically illustrated and described as fall within the scope of the appended claims.

I claim:

l. A substantially rectangular book lid or cover comprising substantially still' sheet material, with a metal binding rim having itsthree members tightly crimped upon and around each of the three outer marginal edge portions of the sheet material, and with a strong and springy reinforcingy element extending longitudinally ofvand held tightly within at least one of the members of said binding rim.

2. A substantially rectangular book lid or cover comprising substantially stili' sheet material having tightly crimped upon and around the three outer marginal edge portions thereof a continuous and hollow metal rim continuously open inwardly to receive said sheet material, said rim comprising a side member, an upper member and a lower member, with strong and springy reinforcing material in strip form extending longitudinally of and tightly held within the hollow interior of each of said members.

3. The combination of claim 2 hereof in which the metal rim is substantially circular in cross view and the corners thereof where the upper and lower members respectively join the side member are rounded in the plane of the cover, and the respective end portions of the upper and lower members normally adjacent to the back of the book are turned inward in the plane of the cover.

4. The combination of claim 2 hereof in which the metal rim is substantially circular in cross view and the corners thereof where the upper and lower members respectively join the side member are rounded in the plane of the cover, and the reinforcing material is of springy metal and is substantially halfround in cross view, extends continuously approximately from end to end of each rim member, and tightly occupies approximately one-half of the hollow interior of each rim member in cross view, the sheet material abutting the reinforcing material throughout the respective lengths of the reinforcing material.

5. A book lid or cover comprising a body of sheet material and a metal marginal binding crimped tightly thereon with the ends the back ofk the book turned inward in the plane of the cover to eiifeot a rounded termnatQn'Of'Sedrendportonse 6. A substantially rectangular book iid or @over of substantially stiif,V sheet material having. tightly crimped around the three outer marginal edge portions therenr1 aA rim formed from. a slngie piece of metal, the rim being of rounded contour in'oross View .and being'roundedg in the plane of the cover at the cornersthereof Where theseveral mem.- bers of the rim join adjacent ones thereof, the endportions respectively of the rim being roundedy inwardly in the plane of; the cover.

ALFRED M. MARTIN. 

